Answer:
I believe it is luminosity and distance
Explanation:
So B
To solve this problem we will apply the concepts related to wavelength, as well as Rayleigh's Criterion or Optical resolution, the optical limit due to diffraction can be calculated empirically from the following relationship,

Here,
= Wavelength
d= Diameter of aperture
= Angular resolution or diffraction angle
Our values are given as,

The frequency of the sound is 
The speed of the sound is 
The wavelength of the sound is

Here,
v = Velocity of the wave
f = Frequency
Replacing,


The diffraction condition is then,

Replacing,

d = 0.24 m
Therefore the diameter should be 0.24m
The letter u before any unit means micro. Micro is a unit
prefix used in the metric system which actually means a factor of 10^-6 (one
millionth).
Now, 10^-6 is equivalent to a movement of 6 decimal places
from left to right. So to write the number 0.0000078 s into a number which has
a unit of us, therefore we move the decimal place by 6 to the right, giving us:
7.8 us
Another way to do this is to multiply the number by 1
million (1,000,000), so:
0.0000078 * 1,000,000
Using the calculator to solve, we get the value:
7.8 us
Answer Expert Verified
Hello here is your answer and also please mark me as brainlest
Since one revolution around a circle is 2 pi radian; hence 1 rpm equals 2 pi radians per minute. And because a minute has 60 seconds, 1 rpm equals 1/60 revolution per second. Therefore, we have 2 pie/60 * 15.3 = 0.2513 rps. The linear velocity v = wr where w is the angular velocity in rad/s and r is the distance. So we have 0.2513 * 10.0 = 2.513 rad/s The centripetal acceleration is given by a = w^2 r = (2.513)^2 * 10 = 63.15 rad/s2 The centripetal force F = mass * centripetal acc = 75 * 63.15 = 4736.25 N The torque = centripetal force * distance = 4736 * 63.15 = 299078.4 Nm Two forces acts on the astronaut. The normal force and acceleration due to gravity.
I hope this help you
brainlest